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Beer-Lambert Law:
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The Beer-Lambert Law relates the absorption of light to the properties of the material through which the light is traveling. It states that the concentration of an analyte in solution is directly proportional to the absorbance.
The calculator uses the Beer-Lambert Law equation:
Where:
Explanation: The equation demonstrates that concentration is directly proportional to absorbance and inversely proportional to both molar absorptivity and path length.
Details: Accurate concentration determination is crucial in analytical chemistry, pharmaceutical sciences, environmental monitoring, and biological research for quantifying substances in solution.
Tips: Enter absorbance (unitless), molar absorptivity in L/mol·cm, and path length in cm. All values must be valid (positive numbers).
Q1: What is the valid range for absorbance measurements?
A: The Beer-Lambert Law is most accurate for absorbance values between 0.1 and 1.0. Values outside this range may lead to less accurate results.
Q2: How is molar absorptivity determined?
A: Molar absorptivity is typically determined experimentally by measuring absorbance of solutions with known concentrations at a specific wavelength.
Q3: What factors can affect the accuracy of this calculation?
A: Factors include chemical deviations (analyte associations/dissociations), instrumental factors (stray light, detector linearity), and physical factors (light scattering).
Q4: Can this equation be used for mixtures?
A: For mixtures, the total absorbance is the sum of absorbances from all chromophores, making the calculation more complex and requiring additional measurements.
Q5: What are typical units for these measurements?
A: Absorbance is unitless, molar absorptivity is typically in L/mol·cm, path length in cm, and concentration in mol/L.